IPAC2013 - List of Authors (Yan, F.)

Paper	Title	Page
TUPWA018	Local Compensation-Rematch for Element Failures in the Low Energy Section of C-Ads Accelerator	1760
	B. Sun, Z. Li, J.Y. Tang, F. Yan IHEP, Beijing, People's Republic of China
	Due to the requirement of high reliability and availability for the C-ADS accelerators, a fault tolerance design is pursued. The effects of transverse focusing element failures in different locations have been studied and the schemes of compensation by means of local compensation have been investigated. After one transverse element failure especially in the low energy section happens, some new methods have been purposed by which the new settings of the neighbouring solenoids and the cavities can be set, and the Twiss parameters and energy can be approximately recovered to that of the nominal ones at the matching point. We find that the normalized RMS emittance in transverse and longitudinal planes have no obvious growth after applying the compensation in each section of the main linac. When we make study on the compensation-rematch for the RF cavity failures, the TraceWin code has been used that doesn’t consider the phase change during the cavity resetting, so a code named LOCCOM, which is based on MATLAB, is developed and used to compensate the error on arrival-time at the matching point.

THPWO043	Progress on the Physics Design of the C-ADS Injector Scheme I	3863
	Z. Li, P. Cheng, H. Geng, C. Meng, H.F. Ouyang, B. Sun, J.Y. Tang, F. Yan, Z. Yang IHEP, Beijing, People's Republic of China
	Funding: Surported by China ADS Project The China ADS (C-ADS) driver linac is composed of two parallel 10 MeV injectors and a main linac which boosts the beam further to 1.5 MeV. There are two design schemes for the injectors based on different working frequency and superconducting cavity structures and are under developing at the same time on IHEP and IMP. The Injector Scheme I, which is proposed by IHEP, works at 325 MHz, the same frequency of the main linac, and superconducting Spoke cavities with geometry beta of 0.12, the same type of cavity as the main linac too, are applied after the RFQ. In this paper, the latest progress on physics design will be presented.

THPWO044	Error Analysis and Beam Loss Control in C-ADS Main Linac	3866
	C. Meng, Z. Li, J.Y. Tang, F. Yan IHEP, Beijing, People's Republic of China
	The China ADS (C-ADS) driver linac is defined to deliver a CW proton beam of 1.5 GeV in energy and 10 mA in current. To meet the extremely high reliability and availability, it is very important and imperative to perform detailed error analysis to simulate the real machine, where the errors always exist. The error studies are by very intense macro-particle simulations by both Trace-Win and TRACK codes with space charge effects included. Through error analysis the proper closed-orbit correction scheme and the maximum tolerable hardware and alignment errors can be found. This paper presents the method to optimize the apertures of elements in the C-ADS main linac. According to the detailed sensitivity analysis of different errors, the static and dynamic errors for the main linac are proposed. The basic lattice scheme has also been re-optimized based on the error studies. The correction scheme is also described, and with the correction scheme the residual orbit can be controlled very well. The influence of the correctors and BPM failures on the correction scheme is also studied.

Paper

Title

Page

Local Compensation-Rematch for Element Failures in the Low Energy Section of C-Ads Accelerator

1760

B. Sun, Z. Li, J.Y. Tang, F. Yan
IHEP, Beijing, People's Republic of China

Due to the requirement of high reliability and availability for the C-ADS accelerators, a fault tolerance design is pursued. The effects of transverse focusing element failures in different locations have been studied and the schemes of compensation by means of local compensation have been investigated. After one transverse element failure especially in the low energy section happens, some new methods have been purposed by which the new settings of the neighbouring solenoids and the cavities can be set, and the Twiss parameters and energy can be approximately recovered to that of the nominal ones at the matching point. We find that the normalized RMS emittance in transverse and longitudinal planes have no obvious growth after applying the compensation in each section of the main linac. When we make study on the compensation-rematch for the RF cavity failures, the TraceWin code has been used that doesn’t consider the phase change during the cavity resetting, so a code named LOCCOM, which is based on MATLAB, is developed and used to compensate the error on arrival-time at the matching point.

THPWO043

Progress on the Physics Design of the C-ADS Injector Scheme I

3863

Z. Li, P. Cheng, H. Geng, C. Meng, H.F. Ouyang, B. Sun, J.Y. Tang, F. Yan, Z. Yang
IHEP, Beijing, People's Republic of China

Funding: Surported by China ADS Project
The China ADS (C-ADS) driver linac is composed of two parallel 10 MeV injectors and a main linac which boosts the beam further to 1.5 MeV. There are two design schemes for the injectors based on different working frequency and superconducting cavity structures and are under developing at the same time on IHEP and IMP. The Injector Scheme I, which is proposed by IHEP, works at 325 MHz, the same frequency of the main linac, and superconducting Spoke cavities with geometry beta of 0.12, the same type of cavity as the main linac too, are applied after the RFQ. In this paper, the latest progress on physics design will be presented.

THPWO044

Error Analysis and Beam Loss Control in C-ADS Main Linac

3866

C. Meng, Z. Li, J.Y. Tang, F. Yan
IHEP, Beijing, People's Republic of China

The China ADS (C-ADS) driver linac is defined to deliver a CW proton beam of 1.5 GeV in energy and 10 mA in current. To meet the extremely high reliability and availability, it is very important and imperative to perform detailed error analysis to simulate the real machine, where the errors always exist. The error studies are by very intense macro-particle simulations by both Trace-Win and TRACK codes with space charge effects included. Through error analysis the proper closed-orbit correction scheme and the maximum tolerable hardware and alignment errors can be found. This paper presents the method to optimize the apertures of elements in the C-ADS main linac. According to the detailed sensitivity analysis of different errors, the static and dynamic errors for the main linac are proposed. The basic lattice scheme has also been re-optimized based on the error studies. The correction scheme is also described, and with the correction scheme the residual orbit can be controlled very well. The influence of the correctors and BPM failures on the correction scheme is also studied.